HR Mainspring No. 258 for Baumgartner 866, 875 - Steel

HR mainspring No. 258 for Baumgartner caliber 866 & 875, steel, new in a likely frail or even barely there envelope. See images for precise mainspring specifications. The envelopes looks like they once saw a visit from a mouse but contents are intact. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.